Walk into the new David Hockney show and it’s like stepping into a vast Disney animation studio.

The walls are lined with identically sized canvases in technicolor acrylic, like the separate frames of a Mickey Mouse cartoon.

For Hockney, at 78, the exhibition – showing Hockney’s friends, family members, staff and acquaintances – is an astonishing burst of youthful vigour.

David Hockney in the Sackler Wing at the Royal Academy of Arts

The whole set was completed in the past three years, and each picture was finished within three days – ‘a 20-hour exposure’, as Hockney characteristically calls it, given his obsession with the relationship between photography and painting.

Sometimes that haste shows. I wouldn’t have recognised the picture of the art critic Martin Gayford without the caption.

Hockney’s line is not as sharp as it was in those two marvellous double portraits: the 1977 picture of his parents and his 1971 painting of the designers Ossie Clark and Celia Birtwell.

He does this wonderfully well – whether it’s the falling folds and precise shadows of the white shirt of an older, fuller-figured Celia Birtwell; or the electric-pink trousers and flamboyant, curling hand gesture of Barry Humphries.

And all with deceptively simple slabs of colour, light and shade.

Because Hockney has painted his subjects in the same chair, with much the same plain background, the differences between them glare out.

Oh, how our body language gives us away!

Jacob Rothschild, the titanic financier, suddenly looks vulnerable, hands laid flat on his knees like a boy in a school photo.

Hockney’s sister Margaret and her friend Pauline Ling in front of their portraits

Hockney’s sister, Margaret Hockney, a nurse, seems relaxed, in control, hands cradled in her lap, her right foot comfortably tucked behind her left.

Some of the portraits would come across as a bit too ultra-simple if shown on their own.

Others, like Margaret Hockney’s, could happily stand alone.

Either way, best to see them all together, in full, wide-screen colour.